Project Summary/Abstract Strategies to prevent mother-to-child transmission (PMTCT) of HIV can reduce the risk of vertical transmission to less than 2%, but difficulties in adhering to the three pillars of PMTCT (maternal ART; exclusive breastfeeding; provision of ART prophylaxis to infant; i.e., Option B+) has led to high rates of MTCT in sub- Saharan Africa and suboptimal maternal and infant health. The goals of the proposed research are to 1) gain an understanding of the influences and mechanisms by which food insecurity (FI) and perinatal depression- two modifiable determinants of PMTCT Option B+ non-adherence-interact to impact Option B+ adherence and 2) refine our conceptual framework to aid in intervention development that assists mothers to maintain Option B+ adherence. Candidate: I am a nurse-scientist with a background in health behavior change theory and infant feeding in the context of HIV. I am applying for a K23 Career Development Award to obtain training, mentorship, and research experience to become an expert and independent investigator in theory-based, multi-level intervention design impacting maternal and infant health in the context of HIV in low-resource settings. Mentoring: I have put together an exceptional mentoring team with extensive experience in HIV treatment and prevention research in Kenya. Drs. Sheri Weiser and Craig Cohen will serve as co-Primary mentors and bring complementary expertise in HIV treatment and prevention, maternal and child health, FI, conceptual framework refinement, and development and implementation of multi-level interventions in Kenya. My co-mentors and scientific advisors round out my team to bring specific content and methods expertise and are based both in the U.S and in Kenya, including: Dr. Mallory Johnson (clinical psychology, multi-level intervention design and evaluation; feasibility implementation; ART adherence); Dr. Monica Gandhi (clinical management of HIV, objective ART adherence); Dr. Elizabeth Bukusi (HIV in the Kenyan context, maternal adherence), Dr. Sera Young (maternal and infant nutrition and FI, PMTCT considerations in intervention design), and Dr. Tor Neilands (psychology, quantitative methods, design and analysis of longitudinal data). Training: I propose to obtain training in FI, perinatal ART adherence, longitudinal quantitative study design and analysis, and theory-based multi-level intervention development and evaluation. Training will be achieved through mentor meetings, coursework, workshops, directed readings and primary research in Kenya. Research: The goals of the proposed research are to 1) identify factors that increase risk for or protect against FI and perinatal depression among HIV+ women during pregnancy and postpartum; 2) investigate the interplay of FI and perinatal depression on adherence to PMTCT guidelines over time among an existing cohort of perinatal women in Kenya; 3) develop a multi-level intervention and test feasibility with full scale testing in a planned R01 submission in year 5.